The patency of a body lumen may be affected by the build-up of tissue or other material in the body lumen. A variety of methods for cutting or dislodging occlusive material and removing such material from a body lumen, such as a blood vessel, have been proposed. For example, tissue-removing catheters may be used to restore the patency of a body lumen. These catheters are intended to cut or excise material from the body lumen and may employ a rotatable tissue-removing element which can be advanced into or past the occlusive material in order to cut and separate such material from the body lumen.
Although these catheters have proven very successful in restoring the patency of body lumens, problems may arise when the tissue-removing element has a smaller diameter than the occlusive tissue. If the tissue-removing element does not maintain contact with the occlusion or lumen wall, the efficacy of the tissue-removing element is reduced.